diff --git a/Library/Homebrew/cask/topological_hash.rb b/Library/Homebrew/cask/topological_hash.rb
index 79c0485bf4..12b6f588e7 100644
--- a/Library/Homebrew/cask/topological_hash.rb
+++ b/Library/Homebrew/cask/topological_hash.rb
@@ -1,4 +1,4 @@
-# typed: false
+# typed: true
 # frozen_string_literal: true
 
 require "tsort"
@@ -8,7 +8,11 @@ module Cask
   class TopologicalHash < Hash
     include TSort
 
-    alias tsort_each_node each_key
+    private
+
+    def tsort_each_node(&block)
+      each_key(&block)
+    end
 
     def tsort_each_child(node, &block)
       fetch(node).each(&block)